Production of primary straight chain alkyl halides



United States Patent 3,278,614 PRODUCTION OF PRIMARY STRAIGHT CHAINALKYL HALIDES Pierre P. H. J. F. Michel, Biviers-Isere, France,assignor, by mesne assignments, to Jadwiga Z. Kubik, Rome, Italy NoDrawing. Filed Oct. 24, 1963, Ser. No. 318,486 Claims. (Cl. 260-658)This application is a continuation-in-part of the co-pending applicationSerial No. 221,441, filed September 5, 1962, now abandoned, entitledProduction of Primary Straight Chain Alkyl Halides. The entiredisclosure of this co-pending application is incorporated herein byreference.

This invention pertains to the production of primary straight chainalkyl halides.

The production of primary straight chain alkyl halides is of importanceat the present time because of certain problems in the field ofsynthetic detergents. These detergents have commonly been referred to assyndets; they are being used in greater and greater quantities. As theiruse increases, various problems caused by them become more and moreserious. To a certain extent these syndets tend to cause corrosion ofequipment and piping. They are well known to interfere with theoperation of conventional types of sewage disposal systems. Frequently,these syndets lead to the presence of foams on various bodies of waterwhere sewage effluents are discharged. In addition, more and moreconcern is being displayed as to the effect of these syndets on the everpresent problem of obtaining portable water supplies.

It is known that synthetic detergents can be manufactured from straightchain aliphatic alcohols and/ or various straight chain alkylbenzenes,and that detergents formed from such compounds are capable ofbiochemical deterioration in conventional sewage systems and hence donot lead to various problems in sewage plant operation, in sewageefiluent foaming and in maintaining satisfactory water supplies as arebriefly indicated in the preceding. Thus, various synthetic detergentsbased upon straight chain alkyl alcohols or alkylben zenes are capableof being decomposed by action of the type achieved in common tricklingfilter, activated sludge and other sewage disposal systems. It isbelieved that they are also capable of being decomposed under naturallyoccurring conditions through bacteriological and other action.Unfortunately, the use of straight chain aliphatic alkyl halides insynthetic detergents has been limited by the relative availability ofthese compounds at a competitive cost. This is because any syntheticdetergent to be acceptable in the present commercial market must bepriced at a comparatively nominal cost.

The present invention has for one of its objectives the production ofvarious straight chain alkyl halides from compounds of the type X(CH CXin which X is a halogen atom. Compounds falling within the range of thisstructural formula can be easily and conveniently manufactured at acomparatively nominal cost at the present time. A closely relatedobjective is to provide a process for the production of intermediatecompounds of this type which can be carried out at a comparativelynominal cost without any significant or unusual production problemsutilizing conventional type chemical equipment.

By way of summary it can be indicated that the present invention isprimarily concerned with the hydrogenation of compounds of the type X(CHCX in which X is a halogen so as to replace the halide atoms in theterminal trihalomethane group with hydrogen without placing the halogenatom at the other end of the linear aliphatic molecule. Suchhydrogenation can be carried out using a conventional hydrogenationcatalyst such as nickel, plati- "ice num or palladium or halides oroxides thereof. The effectiveness of these catalysts can be increased byvarious expedients known to the field of chemistry. This hydrogenationshould preferably be carried out in the absence of air.

Compounds falling within the preceding structural formula can be formedat a comparatively nominal cost by the telomerization of ethylene in thepresence of a carbon tetrahalide such as carbon tetrachloride. Thetelomerization of ethylene to produce these compounds is well known atthe present time and is described in the text, Telomerization and NewSynthetic Materials, Freidlina et al., Pergamon Press, New York, N.Y.(1961). By appropriate variation in reaction conditions and in therelative quantities of the reaction ingredients supplied the length ofthe linear aliphatic chain of compounds falling within the structuralformula as shown by the value of n in this formula can be varied overcomparatively wide limits.

It is presently considered that in practising the present invention Itshould fall within the range of from 4 to 24 inclusive, since withshorter chain molecules it is not believed to be possible to manufacturesatisfactory synthetic detergents, and since with longer chain moleculesvarious solubility problems effectively preclude the formation of adesired type of synthetic detergents.

The catalysts used with the present invention are conventionhydrogenation catalysts. Because of this it is not considered necessaryto set forth in this specification a detailed description of thesecatalysts and of various factors concerning them. A catalyst used incarrying out this invention should, of course, be used in such a form asto provide as much surface area as is reasonably possible in order topromote catalyst activity. Thus, for example, a nickel catalyst used incarrying out the present invention may conveniently take the form ofconventional Raney or extremely finely divided nickel. Platinum andpalladium should, of course, be used in a similar form. These metals canall be disposed on an inert matrix.

It is not normally preferred to utilize as catalysts oxides of platinumand palladium, although if desired they can be used. It is acceptable touse with this invention a nickel oxide catalyst of a conventionalvariety. The various halides of the metals nickel, platinum andpalladium such as the dichlorides of these metals or the tetrachloridesof platinum and palladium can be employed in practising this invention.In general, other halides such as the corresponding bromides, fluoridesand iodides are not used in practicing this invention because of theavailability considerations.

In practicing the present invention, a compound falling within thepreceding structural formula is charged into a conventional autoclaveformed of an inert material with a restricted amount of an inertsolvent. Suitable solvents are saturated hydrocarbon such ascyclohexane, trimethylpentane and the like. In general, preferredresults are obtained by charging the autoclave with from 0.1 by 10 partsby weight of solvent per part by weight of a compound falling within thepreceding structural formula. The amount of catalyst used will of coursedepend upon the effectiveness of the particular catalyst employed.Acceptable results are generally obtained by using from about 0.1 toabout 15 parts by weight of a catalyst as described in the preceding perpart by weight of a compound falling within the preceding structuralformula.

The reaction conditions employed in carrying out the process of thisinvention are of the general type usually employed in hydrogenation.With the present invention temperatures of from 50 C. to 250 C. can besatisfactorily employed. In general, the higher the temperature used themore rapid the reaction. The temperature used during the hydrogenationshould, of course, be below the temperature at which any of thecompounds present in the reaction vessel tend to decompose. If thetemperatures below the lower value given in this range are used thereaction is too slow for practical purposes.

The pressure within the autoclave used for hydrogenation also influencesthe replacement of the halide atoms on the trihalidemethyl group. Ingeneral, pressures from about 0.1 to about 150 kilograms per squarecentimeter can be employed. At lower pressures the desired hydrogenationreaction without the replacement of the terminal halide atoms does notoccur rapidly enough for commercial purposes while pressures fallingabove this range tend to make it diflicult to carry out the desiredreaction and tend to promote undesired reactions within the vesselemployed during the hydrogenation.

A surprising factor which is considered to be the basis of the presentinvention lies in the selectivity of the hydrogenation reaction carriedout. When a hydrogenation reaction is carried out as set forth in thepreceding, the single terminal halide atom in the starting compound isnot replaced by hydrogen, whereas the halide atoms on the trihalomethylgroup at the end of such a compound are completely replaced by hydrogen.Normally, it would be expected that such selective hydrogenation wouldnot occur in practicing the present invention since hydrogenation is nota selective type of process.

The following specific examples are given as an aid to understandingthis invention. From a careful consideration of these examples it willbe realized that this invention can be practiced in other manners thanare specifically set forth in them.

Example 1 A mixture of compounds having a structural formula Cl(CH CClin which n has a value of from 6 to 16 in the amount of 350 grams perweight was charged into a stainless steel autoclave together with 6grams of a conventional palladium or carbon matrix hydrogenationcatalyst and 100 grams of trimethylpentane. Hydrogen was then bubbledthrough the reaction vessel in order to remove any traces of air;thereafter the reaction vessel was closed and raised to the temperatureof about 100 to 110 C. This temperature was maintained throughout thereaction by means external to the autoclave. Hydrogen was then bubbledthrough the reaction vessel at the rate of about 25 liters per hourwhile the pressure in the vessel was maintained about 100 lbs. per sq.inch. After approximately 220 mins. the evolution of hydrogen chlorideceased. The reaction vessel was then cooled. A primary straight chainalkyl halide mixture was then recovered by filtration and distillation.

Example 2 The procedure set forth in Example 1 was followed using amixture of 350 grams of a mixture of compounds having a structuralformula as indicated in Example 1 in which It had a value of from 4 to24, and in which the autoclave was charged with 35 grams cyclohexanesolvent 4 and 35 grams of the catalyst specified in Example 1. Apressure of 150 kilograms per square centimeter was used while thetemperature was maintained at 50 C.

Example 3 The procedure set forth in the preceding Example 1 wasfollowed locating within the autoclave 3,500 grams cyclohexane, 525grams Raney nickel. The reaction in the autoclave was carried out at apressure of kilograms per square centimeter at a temperature of 250 C.

It is to be understood that instead of the chlorides specified in thepreceding examples other corresponding halogen compounds such as thebromides, fluorides and iodides could be used.

I claim:

1. A process for producing a primary straight chain alkyl chloride froma compound having the formula Cl(CH CCl where n is an integer having avalue of from 4 to 25, which comprises:

passing hydrogen in contact with a mixture of at least one compoundhaving said formula, a hydrogenation catalyst and in inert saturatedhydrocarbon solvent while maintaining said mixture at a temperature offrom 50 to 250 C. and while maintaining said mixture under a pressure offrom 0.1 to kilograms per square centimeter so as to cause the terminal-CCl group on said compound to react with said hydrogen, liberatinghydrogen chloride and continuing passing hydrogen in contact with saidmixture until the liberation of hydrogen chloride ceases.

2. A process as defined in claim 1 wherein said mixture contains from0.1 to 10 parts per weight of solvent per part by weight of saidcompound.

3. A process as defined in claim 1 wherein said mixture contains from0.1 to 15 parts per weight of said catalyst per part by weight of saidcompound.

4. A process as defined in claim 1 wherein said catalyst is selectedfrom the group consisting of, nickel, platinum and palladiumhydrogenation catalysts.

5. A process as defined in claim 1 wherein said solvent is cyclohexane.

References Cited by the Examiner UNITED STATES PATENTS 2,427,791 9/ 1947Ipatieif et a1. 260-658 2,440,800 5/1948 Hanford et al. 260-6582,644,835 7/1953 Ladd et al 260-658 X 2,651,664 9/1953 Ladd et al260--658 2,658,929 11/1953 Ladd et al. 26065 2,886,605 5/1959 McClure etal. 260658 X OTHER REFERENCES Freidlina et al.: Telomerization and NewSynthetic Materials, Pergamon Press (1961, pp. 1722).

LEON ZITVER, Primary Examiner.

K. V. ROCKEY, Assistant Examiner.

